Automatic control mechanism for pressure vessels



Aug. 12, 1958 A. G. BLANCHARD AUTOMATIC CONTROL MECHANISM FOR PRESSURE VESSELS Filed March 7. 1945 2 Sheets-Sheet 1 Aug. 1958 I A. G. BLANCHAORD" 2,846,985

AUTOMATIC CONTROL MECHANISM FOR PRESSURE VESSELS Filed March '7, l945 2 Sheets-Sheet 2 United States Patent AUTOMATIC CONTROL MECHANISM FOR PRESSURE VESSELS Alva G. Blanchard, Shreveport, La.

Application March 7, 1945, Serial No. 581,373

i Claims. (Cl. 122-5042) My invention relates to steam boilers and pertains particularly to mechanism employed in connection therewith to control the water in use.

This application is a division of application Serial No. 379,822 (Automatic Control Mechanism for Pressure Vessels) filed February 20, 1941 on which Patent No. 2,395,212 was issued February 19, 1946, which was a continuation in part of my application Serial No. 44,988 (Safety Apparatus for Boilers) filed October 14, 1935 on which division was required, and on which Patent No. 2,233,395 issued dated March 4, 1941. Under the division requirements on my application Serial No. 44,988 filed October 14, 1935 I made the following applications Serial No. 210,585 (Valve Operating Structure) Patent No. 2,199,611 dated May 7, 1940 and Serial No. 322,625 (Pivot Structure) Patent No. 2,362,429 dated November 7, 1944.

In the operation of steam boilers it is desirable to have connected therewith automatic mechanism for controlling the supply of water to the boiler or the fuel, or both, and also to provide for the blowofi of fluid from the boiler when said fluid becomes contaminated.

It is an object of my invention to provide an auto matically operating valve or series of valves through which steam from the boiler may be directed to a plurality of steam operated devices for effecting the control of the water and fuel, or to operate other devices employed in connection with said boiler.

I have as a'further object to provide an eflicient type of compound valve which may effectively operate to deliver steam from a plurality of ports leading from the steam boiler.

The invention also includes an effective means of operating the individual valves in the boiler from a common float, said float being mounted to control the valves in a most effective manner.

The invention resides in the combination of the parts and their construction making up my improvement and attention is called to the drawings herewith wherein the several parts are disclosed.

In Fig. 1 I have shown a perspective view of a boiler towhich the invention may be applied. 7

v Fig. 2 is a side view partly in section illustrating the connection ofthe float with the valve operating lever.

'Figures 3,4, 5 and 6 show one type of multiple valve structure and Figures 7, 8 and 9 represent another type of rnultiplevalve structure.

Figure 3' is a top plan view of the first type of structure.

Figure 4 is a cross sectional view of the same structure along the line 44, Figure 3.

Figure 5 is an end view of the same structure showing the location of the 3 needle valves in relation to their outlets.

Figure 6 is a cross sectional view of the same structure along the line 6--6, Figure 4.

Figure 7 is a top plan view of the second type of structure.

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Figure 8 is a cross sectional view of the same structure, along the line 88, Figure 7.

Figure 9 is a cross sectional view of the same structure, along the line 99, Figure 8.

My invention is adapted for application to any ordinary type of steam boiler. In Fig. 1 I have shown a boiler 1 having the usual fire box 2 and steam chest 3 thereon. Connected with this boiler I provide a float chamber 4. This chamber may be located within the boiler, if desired, but in the preferred embodiment, however, the float chamber is arranged outside the boiler and connected with the upper end of the boiler through a pipe 5. A lower pipe 6 connects with the boiler below the water line so that the chamber 4 will be filled with water to the same level as is the boiler.

With reference to Fig. 2, there is atone side of the valve chamber 4 a nipple 7 preferably welded within an opening in said chamber to hold said nipple securely in position and to provide a reliable seal against the leakage of steam therethrough. At the outer end of the nipple 7 is a threaded seat to receive a valve plug 18, which is screwed tightly therein.

The plug 18 has therethrough a plurality of passages for the outlet of steam from the boiler, each of said passages being connected with a fluid conducting pipe. With reference to Figs. 3, 4, 5, 6, 7, Sand 9 it will be seen that said plug 18 may have a plurality of separate outlets therethrough for the steam. One of said outlets Figure 1 may be connected with an upwardly directed pipe 20 leading to a whistle 21. Another of said outlets 22 may be connected with a pipe 23 leading to the blowoff valve 24. The third outlet may be connected with a pipe 26 leading to the fuel cutoff valve 27. Passages are formed longitudinally of the plug leading to these outlets and each of the pipes 22 and 26 is provided with a restricted bleed port (not shown) to exhaust the fluid in said pipes when the supply thereto is shut off and to prevent a small leak in the needle valves from operating valves 24 or 27.

It will be understood that in the operation of the boiler the supply of water to the boiler may be insuflicient to maintain the proper level of the water in the boiler. As the level of the water in the boiler drops to a height which is suflicient the float 138 will pull the lever arm 62 downwardly. The valve 52 controlling the passage 51 will open first due to the lack of play of the pin 55 within the end of the valve stem. This movement of the valve 52 will open the passage of steam to the whistle and sound an alarm. If no further supply of water is pumped into the boiler the decrease in the level of the water in the boiler will cause the lever arm 62 to engage the inner end of the slot 54 in the valve 53 and pull said valve 53 from its seat, opening up the passage of steam to the fuel cutoff 27 and stop the supply of fuel to the fire box, thus preventing accident to the boiler through failure of a suflicient supply of water therethrough.

If the supply of water to the boiler is in excess of that necessary to maintain the proper level of the water therein, the float 138 will move upward, raising the float arm 62, by the rod 139, thereby bringing the pin 60 into contact with the back of the slot 59 in valve 58, and thereby opening same. This allows steam pressure to pass through 58a and pipes 22 and 23 which opens the blow off valve 24.

When sufficient water has been blown from the boiler to lower the water level to the seating point of valve 58, it will close and the pressure holding the blow off valve 24 closed will be released through a small bleed opening (not shown) in the line 22, thus permitting valve 24 to close. At the end'of each-valve stem is a short arm about which is engaged a spring 56, one end of which is fitted Within a recess 57in the lever arm 62 which tends to hold the valves closed until there is pressure within the valve chamber at which time the pressure holds the valvesclosed. Thespring 61 serves the same purpose onthe lower valve 58.

In Figures 7, 8 and 9 the valve structure is modified. In this form the plug 49 has the same passages for fluid therein asin the previous embodiment and the valves are arranged in the same relative positions. The two upper valves 65 and 66 have men inner-ends extended somewhatfurther and have formed thereon radially extending flanges 67, 68 and 69, the flange 69 forming a head at the inner end of the valve stem. The flange 68 is movable onthe valve and bears against the side walls of an upwardly forked arm 70 on the float arm 71. Thus the pressure of the spring 72 between the flange 67 and the flange orwasher-68-tends to move the valve 66 inwardly and to be compressed by the upward movement of said lever arm.

On the lower side of the arm 71 is another forked arm 73 which receives the end of a valve stem 74 and serves to operate the valve 75 in the same manner as are the upper valves 65 and 66. The lever arm 71 is pivoted upon apin 63 in the same manner as in the previous embodiment and the operation of the valves by a float attached to-the outer end 76 of said arm is the same as in the embodiment disclosed in Figs. 3, 4, and 6.

It will be understood that the downward movement of the arm 71 will compressthe spring 72 on the valve 75 and move the valve to closedposition while the upper valves will be open. Due to the longer distance between the flange 69 upon the valve which controls the fuel line, this valve will be opened slightly later than the opening of the valve leading to the whistle. Thus the valves will operate in the same sequence as "in the other embodiments.

It may become desirable to operate the blowofl valve 24 at intervals so that the impurities in the water in the boiler may beflushed out. This may be accomplished by opening a valve 129 shown in Fig. 1 in the water line 97. If this valve 129 is opened slightly water will feed therethrough to the boiler at a somewhat more rapid rate with the result that the liquid level will rise sufliciently to cause the float valve to open the steam passage leading through the pipe 23 to the blowoff valve and thereby blow the boiler down at frequent intervals, depending on the volume of excess water put into the boiler through valve 129.

Also, it will be noted that steam may be fed directly to the blowofi valve through a pipe 130, which is con nected to a hand-operated valve 131 leading to the boiler. By opening the valve 131 fluid may pass directly through the pipe 130 to operate the blowoif valve in an obvious manner. When the valve 131 is closed a tap 132 adjacent thereto may be opened to bleed fluid from the line 130.

It will be seen that I have provided a plurality of control devices for regulating the passage of steam from the'boiler to any of a number of operated devices exterior to the boiler. Each of these devices functions in an economical manner through the operation of a float connected with the steam boiler. This construction is a simple and economical one and easily attached to any boiler in ordinary use.

The invention claimed is:

1. In a safety apparatus for boilers, the combination of a fuel supply conduit, a valve in said conduit, means for'yieldingly holding said valve open, a compartment, a pressure responsive means to respond to pressure in said compartment arranged to close the valve, a housing, a plurality of outlet passages through said housing, a needle valve in each of said passages, single means responsive to conditions within said boiler to open said 4 valves in sequence, a conduit connecting the last of said sequentially opening valves to open with said compartment to supply fluid under pressure from said housing to said compartment to force said fluid against the pressure responsive means, and a conduit connecting another of said sequentially opening valves to an audible alarm actuating mechanism.

2. In a safety apparatus for boilers, the combination of a fuel supply conduit, a valve in said conduit, means for yieldingly holding said valve open, a compartment, a pressure responsive means to respond to pressure in said compartment arranged to close the valve, a housing, a plurality of outlet pasasges through said housing, a needle valve in each of said'passages, a float operated lever fulcrumed within said housing, sequentially functioning connections between said valves and said lever operated by downward movement of said lever, a conduit connecting the last of said sequentially opening valves to open with said compartment to supply fluid under pressure from said housing to said compartment to force said fluid against the pressure responsive means, a conduit connecting another of said sequentially opening valves to an audible alarm actuating mechanism, and means to relieve the fluid pressure in said compartment.

3. A housing, a plurality of outlet passages through said housing, a valve in each of said passages, one of said valves communicating with an alarm for low water and another of said valves communicating with a fuel shut-01f device, a lever fulcrumed within said housing, a float on the end of said lever, an operative connection between said lever and said low water alarm valve when said float is in one position and an operative connection between said lever and said fuel shut-off valve when said float is in a lower position.

4. An audible alarm actuating mechanism, a fuel shut off valve and a control unit including a plurality of needle valves sequentially operated by a single means responsive to water level within a boiler, one of said valves having an operable connection with said mechanism to operate said mechanism at a predetermined level of water within said boiler, and another of said valves having an operable connection with said fuel shut off valve to operate said fuel shut off valve after said level of water has fallen below said predetermined level.

5. In a safety apparatus for boilers, the combination of an audible alarm actuating mechanism, a fuel shut off valve and a control unit including a plurality of needle valves sequentially operated by a single means responsive to a variable condition within a boiler, one of said valves having an operable connection with said mechanism to operate said mechanism at a predetermined value of said condition within said boiler, and another of said valves having an operable connection with said fuel shut off valve to operate said fuel shut off valve at anothervalue of said variable condition.

References Cited in the file of this patent UNITED STATES PATENTS 485,976 Newman Nov. 8, 1892 502,191 Hodgson July 25, 1893 521,169 Kirchner June 12,1894 575,933 Parker Ian. 26, 1897 590,884 Garrig'us Sept. 28, 1897 620,287 Donnelly Feb. 28, 1899 1,004,896 Neville Oct. 3, 1911 1,129,561 Duggan ..'Feb. 23, 1915 1,297,249 Rice Mar. 11, 1919 1,561,412 Davis Nov. 10, 1925 1,601,907 Christensen Oct. 5, 1926 2,183,422 Brown Dec. 12, 1939 2,199,611 Blanchard May 7, 1940 2,227,405 Brown Dec. 21, 1940 2,233,395 Blanchard Mar. 4,1941 

